ARION ATER. 169 
The CEPHALIC RETRACTORS arise from three dis- 
tinct and separate points, as is usual in the genus ; 
the PHARYNGEAL muscle originating most posteri- 
orly nearly in the median line behind the lung 
cavity, and bifureating about half-way for attach- 
ment to each side of the buecal bulb; the TENTA- 
CULAR retractors are broad and flat, the left arising 
from the hinder left-side of the lung periphery ; the A 
right retractor is somewhat similarly placed, but a 
trifle removed from the lung; both divide about the 
middle of their course into a chief muscle for the 
ommatophore of their respective sides of the body, 
and a subsidiary one for the lower tentacle, the 
latter branching again to send a slip to the buccal Bis. 1912 Ceahalic renmactals o€ 
or labial lobe. Aap Gi 
The REPRODUCTIVE ORGANS are comparatively simple; the dark-brown spherical 
OVOTESTIS is placed behind the stomach, and is traversed medially by an artery ; 
the HERMAPHRODITE DUCT is long and tortuous, terminating in a slightly swollen 
and acutely bent junction with the ovispermatoduct, representing the VESICULA 
SEMINALIS ; the pale ALBUMEN GLAND is large and compact, but much indented ; 
the OVISPERMATODUCT is very long ; the OVIDUCT is a delicate bluish rutile above, 
EE 
a 
Fic. 192. Fic. 193. Fic. 195, Fic. 196. 
The Reproductive system of adult and juvenile A77on ate (L.), showing the muscular arrangements 
and the modifications of the organs arising during growth x 3. 
Fic. 192.—The proximal end of the organs with the epiphallus removed to show the arrangement 
of the retractor and attachment of the spermatheca. 
Fic. 193.—The organs as seen from the opposite side, with oviduct and genital retractor removed. 
Fic. 194.—Spermatheca and oviduct, showing attachment of retractor. 
Frc. 195.—Proximal end of sexual organs, showing their complex natural arrangement. 
Fic. 196.—Sexual organs of an immature example. 
alb.g7. albumen gland ; Z.a¢. glandular lower atrium ; 7.a¢. and a@¢. upper atrium 3; of. ovotestis ; 
ov. oviduct ; osd. ovispermduct : ef. epiphallus, cut short ; sf. spermatheca ; v.d@. vas deferens ; 
ry. genital retractor, showing attachment to spermatheca duct, oviduct, and atrium. 
narrowing below, while the yellowish SPERM-DUCT, or prostate, increases in calibre 
as it descends ; the two channels being closely connected together ; the slender VAs- 
DEFERENS expands into a thick EPIPHALLUS, which secretes the moderately slim, 
brownish, and dentienlate spermatophore ; the ovately-globose SPERMATHECA is 
connected by a shortish stalk with the atrium, into which the epiphallus, oviduct, 
and spermatheca all debouch; the upper ATRIUM, or ‘‘egg-sac,” is immensely bulged 
at one side, the protuberance originating at the base of the oviduct, and contains 
an erectile linguiform appendage, which is probably a SARCOBELUM. The GENITAL 
